This invention relates in general to brake systems for ground vehicles, and in particular to electro-hydraulic brake systems with normal braking pressure supplied by an electrically driven pump.
Electro-hydraulic braking systems with manually powered backup systems have been shown in some publications. For example, German Patent Application DE 4413579A1 illustrates a system having a manually powered master cylinder connected through isolation valves to brakes at a vehicle's wheels. When the isolation valves are shut, pressurized brake fluid from the master cylinder is delivered to a pedal simulator. Pressure transducers are used to develop a signal representative of a desired braking effort, which is fed to an electronic control unit. The electronic control unit controls the operation of motor operated braking pressure generators (pumps) to correspondingly deliver pressurized hydraulic brake fluid to the vehicle brakes.